Back on Sept. 21 I covered a seminar on hurricanes and climate change. Five scientists presented some of their latest research into the topic. It was an excellent event – and quite an education for me.
Dr. Kerry Emanuel, a professor of atmospheric science at M.I.T., opened the seminar by describing the three approaches scientists use to analyze hurricane behavior and its relation to climate change: observations, theory, and computer models.
These approaches each have their strong and weak points, but as Emanuel said, “What we
understand is based on all three.”
I took this to mean that one model or one discovery is not going to fully explain the hurricane-climate change relationship. Instead, all of the approaches and findings have to be considered together as a whole.
One surprising thing (at least to me) mentioned by several of the scientists was that hurricane frequency could actually decrease as the climate and sea surface temperatures warm up (warm sea temperatures are one of the conditions necessary in order for a hurricane to form). Also surprising was how future projections don’t seem to jibe with what we’ve observed over the last three to five decades.
In an e-mail a week later, Emanuel clarified things a bit for me. The three research approaches, he said, “are not in complete convergence at the moment. It is clear that hurricane activity, as measured by several metrics, has increased a great deal in the Atlantic over the past century, and particularly the last decade, and it is also clear that this has proceeded more or less in lock step with tropical Atlantic ocean temperature. But these increases are more than were predicted using theory and models, and we still do not understand why. These same models, and what theory exists, predict somewhat more modest changes going into the future.”
He noted that models and theory predict that hurricane winds and rainfall will increase as the climate warms, but they also “greatly underpredict what has already happened with storm power.” At the seminar he explained that storm power is the total amount of energy generated by a hurricane over its lifetime, and that storm power has doubled since the 1980s. Atlantic sea surface temperatures have had a strong correlation with storm power.
As for hurricane frequency – the number of storms each year – studies do not agree on whether we’ll see more or fewer hurricanes as the climate warms.
Emanuel explained via e-mail, “Most models predict declining frequency of events, but there are exceptions, and even models that predict global declines sometime predict that individual regions will suffer increases. For the Atlantic, the results are too diverse to be meaningful on the frequency issue.”
I find this kind of big-picture overview valuable. It’s not something we often see in the media when the latest hurricane study or press release comes out.
ooooohhhh..thats good. i remember the cries of this years hurricane season will surpass last year due to climate change. and once again it has not come to pass. but now that year two goes by suddenly someone remembers it was predicted that global warming can cause fewer hurricanes it all comes together? climate change has occured over and over and over again. but whatever.
In 2007 seasonal Atlantic storms we can observe that two predominant factors wind shear (hinders development of storm) and faster intensification of storm very near coast.
Wind shear played major role in obstructing the storm development. Does Wind shear has any correlation with SST? Many of the Tropical Storms and Hurricanes which made landfalls, intensified their strength few hours before landfall (created records), does it have any climatic significance?
GLOBAL CHALLENGE TO GOOD SCIENCE, HUMAN WELLBEING AND ENVIRONMENTAL HEALTH:
Global-Warming Deniers: A Well-Funded Machine
by: Sharon Begley 6 August 2007 Newsweek
http://www.msnbc.msn.com/id/20122975/site/newsweek/
Sam, hurricane frequency and hurricane intensity are two separate issues. If hurricanes decrease in number over the coming decades - but become more powerful and more destructive - well, I’ll just say it won’t make me want to buy a house along a coastline …
In an earlier story from Dan on this seminar, Kerry Emanuel pointed out that there just aren’t all that many hurricane researchers … not as many as earthquake researchers, for example.
No one is saying “let’s worry” or “let’s don’t worry.” But, given the destructive power of hurricanes, they are definitely something to watch, wonder about, and study with all the scientific tools at our disposal.
Deborah
Hurricanes are very deadly - and have experienced some very brutal storms in my lifetime. But the majority of people don’t think that Hurricanes can be as dangerous as an earthquake or an erupting volcano and hardly take any precautions. It would be more interesting, perhaps, if weather forecasters or anchors could use more information from all branches of science to save more lives.
I agree with Jackie. Didn’t we just lose a major American city to a hurricane? I don’t want to be negative about New Orleans, but here in central Texas I know we are still seeing evacuees.
More researchers and more research needed!
Deborah
It was very terrible what happened in New Orleans. With the rebuilding that’s still not finished, I worry about the risk of keeping the city in the same place given it’s low elevation in relation to the land around it. It’s horrible when catastrophes like this happen, and we can only do our best to prepare and hope for the best.
You’ve got to keep in mind that the bulk of New Orleans was well below the water level on the other side of the levees many many times in its history…I’ve stood on the levee near Jackson Square and watched the barges go by way above the street level at the square. Local corruption and incompetence in the levee board and inattention from whoever designed , built, or did QA inspection on a couple of key places on that levee is why it failed, not from the supposed intensity of Katrina, which had already drastically declined. If you build low, it will eventually flood, when all unfavorable circumstances collide.
Global Warming (manmade or other) had as much to do with Katrina as the price of tea in China affects the win-loss record of the Chicago Cubs.
Two remarkably sound responses follow in the link just below to the ubiquitous commentaries we see in the mass media day after day that extoll the virtues of economic globalization and try to debunk the scientific consensus on climate change.
http://www.youtube.com/profile_videos?user=policyalternatives&p;=r
If time does not permit the viewing of the complete presentations by Naomi Klein and David Suzuki and you have not more several minutes to view a single part, let me tentatively say that the part I find most helpful and responsive to the many climate change DENIERS and NAYSAYERS can be found in Part 5 of the six part series presented by David Suzuki.
Global Warming (manmade or other) had as much to do with Katrina as the price of tea in China affects the win-loss record of the Chicago Cubs.
Doug … you just don’t know that. You just can’t say that for certain. Again I say … more research is needed.
Deborah
Doug — A big reason New Orleans flooded during Katrina was because of a misguided Army Corps of Engineers project called the Mississippi River Gulf Outlet, or MR-GO. Built in the 1960s as a canal for ships to get from New Orleans out to the Gulf more quickly (and not have to navigate the serpentine Mississippi River, MR-GO runs a straight 40 miles from the city to the Gulf. The locals call it “hurricane highway” because storm surges can rush right up it and flood the city — which is what happened during Katrina. This “canal” is more than a half-mile wide in some places — it sounds more like a man-made river. Building it destroyed many of the wetlands and cypress swamps that used to protect the city from storm surges. An article in the September/October 2007 Worldwatch magazine calls the flooding of the city a “manmade catastrophe.” See http://www.worldwatch.org/ww/katrina2
Also, don’t downplay the intensity of Katrina. As the National Climatic Data Center summary states (http://www.ncdc.noaa.gov/oa/climate/research/2005/katrina.html), Katrina was one of the most powerful storms to hit the U.S. in the last 100 years. The storm track map on that page, and this summary from the National Weather Service (http://www.srh.noaa.gov/mob/0805Katrina/), note that Katrina was a Category 4 storm (140 mph winds) when it made first landfall at Grand Isle, La., south of New Orleans. When it made second landfall in Mississippi, it was a strong Category 3 with 125 mph winds. But it was plenty ferocious and the storm surges along the Gulf Coast attest to that.
I wonder if G*d is ever in your view when your talking about all you do about Global warming? It is a Prophecy for the endtimes that these things will come to past, and I wonder if you ever take anything as truth from such sources like the book of Revelations in the Bible?
Susana
abcquilts007@aol.com
I believe we’ll see more storms and hurricanes next year, this has been increasing for years now. Even in countries where there wasn’t destructive storms, they are showing more and more, along with floods.
may God have mercy on us!
I live in a Hurricane prone area. New Orleans is a city that now lies below sea level and it is slowly sinking even more. Plus the people solely depended on Washington. Strong levees and strong pumps keep New Orleans dry just like my area but minus the pumps. The hurricanes that have raveraged this area have been 23, 40, 74 years ago, when GW was not in the lexicon.
If a hurricane should come this way, and it will at a future date, the levees would probaly break, because they are old and have grown weak over time. This is a failure of local governments and of Washington and not of GW.
Houses built at grown level will flood, and some of them are expensive. It makes me wonder what they use for brains to build at ground level! The old timers have learned what the people of Mississippi learned and that is that not to solely depend on help from Washington.
There is observational evidence for an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures. There are also suggestions of increased intense tropical cyclone activity in some other regions where concerns over data quality are greater. Multi-decadal variability and the quality of the tropical cyclone records prior to routine satellite observations in about 1970 complicate the detection of long-term trends in tropical cyclone activity. There is no clear trend in the annual numbers of tropical cyclones. The apparent increase in the proportion of very intense storms since 1970 in some regions is much larger than simulated by current models for that period.
We had a powerful hurricane come ashore in a desolate part of Texas and very few people noticed. A “normal” hurricane makes a direct hit on New Orleans and all the media notices as well as the world. This world has gone through many cooling and warming cycles before and man can talk about the weather all he wants but he can’t change it.
I agree with Jackie. Didn’t we just lose a major American city to a hurricane? I don’t want to be negative about New Orleans, but here in central Texas I know we are still seeing evacuees.
More researchers and more research needed!
Deborah
With the rebuilding that’s still not finished, I worry about the risk of keeping the city in the same place given it’s low elevation in relation to the land around it. It’s horrible when catastrophes like this happen, and we can only do our best to prepare and hope for the best.
There is no clear trend in the annual numbers of tropical cyclones. The apparent increase in the proportion of very intense storms since 1970 in some regions is much larger than simulated by current models for that period.
What really does make a difference, of course, is that the population of these coastal regions has exploded. And people are…their risk is being subsidized by federal policy, and state and local policy, and that is what the real problem is. It’s not meteorological, it’s societal. We’re putting all this wealth in harm’s way and we’re getting creamed.
I believe we’ll see more storms and hurricanes next year, this has been increasing for years now. Even in countries where there wasn’t destructive storms, they are showing more and more, along with floods.
We had a powerful hurricane come ashore in a desolate part of Texas and very few people noticed. A “normal” hurricane makes a direct hit on New Orleans and all the media notices as well as the world. This world has gone through many cooling and warming cycles before and man can talk about the weather all he wants but he can’t change it.
I believe we’ll see more storms and hurricanes next year, this has been increasing for years now.
Didn’t we just lose a major American city to a hurricane? I don’t want to be negative about New Orleans, but here in central Texas I know we are still seeing evacuees.